fixed copylight headers

Author: sashingo

PWGHF/HFL/Tasks/taskElectronWeakBoson.cxx

@@ -1,4 +1,5 @@
-// See https://alice-o2.web.cern.ch/copyright for details of the copyright holders of ALICE O2.
+// Copyright 2019-2020 CERN and copyright holders of ALICE O2.
+// See https://alice-o2.web.cern.ch/copyright for details of the copyright holders.
 // All rights not expressly granted are reserved.
 //
 // This software is distributed under the terms of the GNU General Public